The overall objective of this research program is to biosynthetically produce new aminoglycosidic aminocyclitol antibiotics related to streptomycin and mannosidostreptomycin but with a wider antibiotic spectrum, more potent activity, a lower degree of toxicity and a greater activity against drug-resistant microorganisms. Our objective is to produce molecules with various aminocyclitol derivatives replacing the streptidine moiety of streptomycin. This will be done by producing mutants of Streptomyces griseus which are deficient in their ability to produce streptidine endogenously and feeding them other aminocyclitol derivatives. A further objective is to attach various sugars to the C-4 of the L-methyl glucosamine moiety in the same way that mannose is attached in mannosidostreptomycin. A combination of these two objectives in a single molecule could lead to extremely useful bactericidal antibiotics capable of combating many infectious diseases, molecules which cannot be produced by the traditional techniques of industrial fermentation.